[en] Following coma, some patients will recover wakefulness without signs of consciousness (i.e., vegetative state) or
may show nonreflexive movements but with no ability for functional communication (i.e., minimally conscious
state). Currently, there remains a high rate of misdiagnosis of the vegetative state. The increasing use of fMRI and
EEG tools permits the clinical characterization of these patients to be improved. We first discuss “resting metabolism”
and “passive activation” paradigms, used in neuroimaging and evoked potential studies, which merely identify
neural activation reflecting “automatic” processing—that is, occurring without the patient’s willful intervention.
Secondly, we present an alternative approach consisting of instructing subjects to imagine well-defined sensorymotor
or cognitive-mental actions. This strategy reflects volitional neural activation and, hence, witnesses awareness.
Finally, we present results on blood-oxgen-level-dependent “default mode network”/resting state studies that
might be a promising tool in the diagnosis of these challenging patients.